I have put 200 miles on a 2007 S40 (purchased with 3600 miles) and enjoy the burble on deceleration but detest the rifle crack of the after fire. I read the post dealing with the idle mixture screw and also one suggesting the exhaust header acorn nuts we correctly tightened.

I did both and took it on a 11 mile ride with speeds from 55 to 15. I made a point to close the throttle hard every time I could. In the past, this always seemed to result in an after fire. Except for one rifle crack, nothing but that great deceleration sound.

My question and concern is the stability of the idle mixture screw. It did not have very much resistance during adjustment. Does anyone see any issues with putting some silicone sealer over the screw to hold it in place or is there a better solution?

Thanks